Editing TECO (text editor) (section)

==Impact==
The [[EMACS]] editor originally started by [[David A. Moon]] and [[Guy L. Steele Jr.]] was implemented in TECO as a set of Editor MACroS. TECO became more widely used following a [[Digital Equipment Corporation]] (DEC) [[PDP-6]] implementation developed at MIT's [[Project MAC]] in 1964. This implementation continuously displayed the edited text visually on a [[CRT screen]], and was used as an interactive online editor. Later versions of TECO were capable of driving full-screen mode on various DEC [[RS-232]] video terminals such as the [[VT52]] or [[VT100]].

TECO was available for several operating systems and computers, including the [[PDP-1]] computer, the [[PDP-8]] (under OS/8),<ref name=StdTeco>{{cite web
|quote=Standard TECO. Text Editor and Corrector for the. VAX, PDP-11, PDP-10, and. PDP-8. 
|url=https://livingcomputers.org/Discover/Online-Systems/User-Documentation/OpenVMS-7-3/3_(Editor)_DEC_Standard_TECO.aspx
|title=Standard TECO Text Editor and Corrector}}</ref><ref>{{cite web
|title=Doug Jones's DEC PDP-8 FAQs
|url=http://homepage.divms.uiowa.edu/~jones/pdp8/faqs
|quote=What programming languages were supported on the PDP-8? ... TECO, the text editor, was included in the standard OS/8 distributions}}</ref> the [[Incompatible Timesharing System]] (ITS) on the PDP-6 and [[PDP-10]], and [[TOPS-10]] and [[TOPS-20]] on the [[PDP-10]]. A version of TECO was provided with all DEC operating systems; the version available for [[RT11]] was able to drive the GT40 graphics display while the version available for [[RSTS/E]] was implemented as a multi-user [[run-time system]] and could be used as the user's complete operating environment; the user never actually had to exit TECO. The VTEDIT (Video  Terminal  Editor) TECO macro was commonly used on [[RSTS/E]] and [[VAX]] systems with terminals capable of direct-cursor control (e.g. [[VT52]] and [[VT100]]) to provide a full-screen visual editor similar in function to the contemporaneously developed [[Emacs]].

TECO continues to be included in [[OpenVMS]] by VSI, and is invoked with the <code>EDIT/TECO</code> command.<ref>{{cite web|url=https://vmssoftware.com/docs/VSI_DCL_DICT_VOL_I.pdf|website=vmssoftware.com|access-date=2020-09-13|date=April 2020|title=VSI OpenVMS DCL Dictionary: A-Z}}</ref>

A descendant of the version DEC distributed for the PDP-10 is still available on the Internet, along with several partial implementations for the [[MS-DOS]]/[[Microsoft Windows]] environment.